The present invention relates to conveyors and, more particularly, to conveyors used to unscramble articles that are received in a random order.
Unscrambling conveyors are positioned between an input conveyor, which delivers articles to the induct or charge end of the unscrambler conveyor, and an output conveyor, which receives articles at the discharge end of the unscrambler conveyor. Unscrambler conveyors typically use skewed rollers that transport articles, which are received at the induct end, in a longitudinal and lateral direction across the conveying surface of the unscrambling conveyor towards one side of the conveyor to align the articles and thereafter discharge the articles from the discharge end of the unscrambling conveyor to the output conveyor. Furthermore, existing unscrambling conveyors use tapered rollers, which define a low side and a high side of the conveyor and move the articles toward the low side when unscrambled. The rollers are typically driven by a belt drive system, which heretofore, has driven the rollers at their low side. As a result, on occasion, the drive assembly may interfere with the unscrambling of the articles.
As conveyor systems increase their efficiency, the speed of the components of conveyor systems has increased. This increase in speed, however, places more of a demand on some components than others. Typically the rollers of unscrambler conveyors must operate at faster speeds than the rollers of the input or output conveyors. For example, most unscrambler conveyors operate at twice the speed of the input and output conveyors in order to maintain the flow of articles through the system. Until recently, these tapered rollers have been metal rollers or straight metal rollers with segmented polyethylene sheathes that are mounted and stacked on the respective rollers to define the conveying surface of the conveyor. The tapered metal rollers, though capable of operating at higher speeds, generate high and usually unacceptable noise levels when operated at higher speeds. For example, when these metal rollers operated to generate a conveyor speed of 400 ft/minute or greater to meet input/output conveyor speeds of about 200 ft/minute, the noise generated by these metal rollers is unacceptable. Rollers with segmented polyethylene sheathes have been found to deteriorate with use over a relatively short period of time and, further, are not durable or impact resistant. Furthermore, when the operated at higher speeds, for example to produce a conveyor speed of 400 feet/minute, the segmented sleeves have been found to deteriorate even faster.
With input and output conveyors operating at conveyor speeds of 200 feet/minute or greater, it has been found that the current unscrambler conveyor designs cannot, therefore, support these increased conveyor speeds without deteriorating or generating unacceptable noise levels. As noted above, typically, an unscrambling conveyor must be operated at a higher speed than the input conveyors, such as twice the speed, in order to provide a continuous throughput for the conveyor system. Therefore, the existing unscrambler conveyors have become a limiting factor in current high speed conveyor systems.
Accordingly, there exists a need for an unscrambling conveyor that can effectively unscramble a large volume of packages at a rate that is commensurate with the existing high speed conveyor equipment without generating unacceptable noise levels and, further, in a manner to provide increased longevity to the components.